Synergistic and Green Electrocatalytic Behavior of a BaFe₂O₄@g-C₃N₄ Nanocomposite for Sensitive Vandetanib Detection

Abstract Vandetanib (VAN), a multi-targeted tyrosine kinase inhibitor used in the treatment of medullary thyroid carcinoma, requires sensitive and accurate quantification in biological matrices. A novel BaFe₂O₄@g-C₃N₄ nanocomposite-based glassy carbon electrode (BaFe₂O₄@g-C₃N₄/GCE) was developed in this study for sensitive electrochemical determination of VAN. The prepared materials were thoroughly characterized by FTIR, XRD, TGA, BET surface area measurement, FE-SEM, EDS, and elemental mapping, indicating the homogeneous dispersion of BaFe₂O₄ nanoparticles on g-C₃N₄ sheets and the formation of a porous, electroactive architecture. The integration of BaFe₂O₄ with g-C₃N₄ enhanced the electrocatalytic activity of the modified electrode toward VAN oxidation. Differential pulse voltammetry enabled VAN quantification over a wide linear range of 0.06–2.93 µM with an excellent correlation coefficient (R² = 0.997) and a low quantification limit of 0.0075 µM. The sensor demonstrated outstanding reproducibility, stability, and anti-fouling behavior. The analytical applicability of the developed sensor was verified through the determination of VAN in human serum, urine, and pharmaceutical formulations, with satisfactory recoveries ranging from 99.11% to 101.71% with RSD values below 3%. In addition, greenness and applicability assessments using GEMAM and BAGI confirmed the environmental compatibility, operational simplicity, and practical feasibility of the proposed method.